Recovering the social rent reduction after concealed property: calculation, time limit and procedure

The social rent is calculated on the basis of the tenant’s income and household composition and is below the market value of the home. The difference between the rent the tenant pays and the base rent, the rental value of the home on the market, is the social rent reduction. It is financed with public money and is the benefit that the social rental system grants the tenant.

Flemish regulations provide that the tenant is entitled to that reduction only if they provide the landlord with all necessary information and that information is not fraudulent. Anyone who conceals a home or building land at registration or during the tenancy does not meet this requirement. The reduction for that period has then been paid unduly and can be recovered, in addition to termination of the lease.

The calculation is in principle simple: per month, the difference between the base rent and the rent paid, added up over the period in which the tenant did not satisfy the property ownership condition. In practice, this requires three findings.

The start date. This is the date on which the tenant became the owner, or 1 March 2017 if the ownership is older and the tenant was already renting at that time. The register extract from abroad states the date of acquisition; in the case of an inheritance, that is the date of death or of the deed of inheritance. That is why we always have that date included in the report.

The end date. The date on which the tenant left the home or disposed of the property. Since 1 October 2025, partial ownership no longer counts; for a tenant who owned only an inherited share, the recoverable period then ends on 30 September 2025. See the new property ownership condition.

The base rent per year. The housing company itself has the market value and the annual adjustments. Attach the calculation per year to the claim; courts want to be able to check the sums.

Rent and the difference in rent are periodic debts. For such claims, Belgium applies in principle a limitation period of five years from each due date. A housing company can therefore usually claim the reduction for the last five years, counted from the summons or an interrupting formal notice. In the case of fraud, a longer period is sometimes argued; have that point assessed by your counsel and in any event do not delay the formal notice once the report is in.

In the Woonhaven case, it concerned nine years of rent reduction, a total of about 50,000 euros including investigation costs; in Antwerp 2020, 13,210.07 euros. The amounts can add up quickly, which is why investigation in case of a concrete suspicion may be worthwhile. Whether recovery is possible depends on the individual case and the assessment by the competent authority or the court.

The rulings differ on the costs of the investigation. The justice of the peace in Hamme ordered the tenant to pay the search costs; the court of first instance of Antwerp in 2020 did not award the costs of the report and translation; in the Woonhaven case they formed part of the claim. Always claim the investigation costs separately, therefore, with the invoice and an explanation of why the investigation was necessary. For Flemish housing companies, there is also the reimbursement by Wonen in Vlaanderen: in full in the event of a hit, 75 percent without a hit, via the framework agreement.

1. Hearing. Invite the tenant, present the report and record their statement. A settlement sometimes follows: sale of the property, departure from the home and a payment plan.
2. Formal notice. Send a registered letter with the termination or the announcement of it, the calculation of the reduction and a payment deadline. This interrupts the limitation period.
3. Justice of the peace. Rental disputes are heard by the justice of the peace of the place where the home is located. Claim the dissolution or confirmation of the termination, the reduction with interest, the investigation costs and the costs of the proceedings.
4. Enforcement. If a judgment is not complied with, attachment follows in Belgium or, if the tenant has left and owns property abroad, possibly recovery against that property; the feasibility of this is assessed per case. See recovery and seizure abroad.

What the courts have decided so far is described in what the Belgian courts say.

Sources: Vlaamse Codex Wonen and Besluit Vlaamse Codex Wonen; Business AM, 11 December 2020; VRT NWS, 27 March 2024.